Forty-eight crossbred pigs were assigned to one of six dietary treatments in a 6 x 2 (treatment x sex) factorial arrangement. Diets were based on wheat and canola meal and were formulated to contain 0%, 4.9%, 9.7%, 14.6% or 19.4% wheat distillers' dried grains with solubles (DDGS) during the growing period and 0%, 4.0%, 8.1%, 12.1% and 16.1% wheat DDGS during the finishing period. The addition of wheat DDGS was made at the expense of both wheat and canola meal. A feed flavour was added to the diet in which wheat DDGS supplied 100% of the supplementary protein. Over the entire experimental period (21.5-112.2 kg), increasing the level of wheat DDGS resulted in a linear decrease in weight gain and feed conversion ratio. Feed intake was linearly reduced by inclusion of wheat DDGS during the growing period (21.5-57.4 kg) but not the finishing period (57.4-112.2 kg). Increasing the level of wheat DDGS in the diet resulted in a linear decline in carcass value index and lean yield while loin fat linearly increased. The addition of a flavour to the diet in which DDGS supplied 100% of the supplementary protein had no effect on performance or carcass traits.